A while ago I randomly started playing "Kirby's Adventure" for the NES for the very first time in my life.
I think I played for about 15 minutes before I got a Game Over, and this happened while I was fighting some giant tree or something;
I believe it was Stage 5.
Anyway, I thought the controls felt slightly unintuitive at first, and I spent some time trying to figure out what exactly I was supposed to do in order to fly and use special abilities, but after that, it was pretty fluent.